Morrison betrayed Australia: ex-minister

Scott Morrison should quit parliament after he "betrayed" the Australian people following revelations he secretly swore himself into several ministerial portfolios, former home affairs minister Karen Andrews has declared.

Prime Minister Anthony Albanese revealed on Tuesday Mr Morrison had appointed himself to the finance, treasury, health, home affairs and resources portfolios in secret.

They were made between March 2020 and May 2021.

Ms Andrews said Mr Morrison, the MP for the Sydney seat of Cook, should resign from parliament.

"The Australian people have been let down, they have been betrayed," she told AAP.

"For a former prime minister to have behaved in that manner, to secretly be sworn into other portfolios, undermines the Westminster system, it's absolutely unacceptable.

"If there were reasons for the prime minister to be sworn into other portfolios then they should have been made public, whereas it's been made public now by default."

Ms Andrews said she wasn't told Mr Morrison had been sworn into her portfolio by the prime minister himself, the Prime Minister's Office or the department secretary.

"I have absolutely no knowledge ... if any of those people knew, they did not tell me," she said.

Publishing a response on Facebook, Mr Morrison said the pandemic and economic downturn required an "unprecedented policy response".

"The risk of ministers becoming incapacitated, sick, hospitalised, incapable of doing their work at a critical hour or even fatality was very real," he wrote.

"The home affairs minister was struck down with COVID-19 early in the pandemic, and the UK prime minister was on a ventilator and facing the very real prospect of dying of COVID-19."

When asked, Opposition Leader Peter Dutton wouldn't call for Mr Morrison's resignation, saying it was better to wait for the legal advice.

The solicitor-general is due to provide advice to Mr Albanese next Monday.

Greens attorney-general spokesman David Shoebridge said the party was seeking advice on how to refer Mr Morrison to parliament's privileges committee.

Former treasurer Josh Frydenberg told The Australian he was not aware of Mr Morrison's decision to take on the treasury portfolio.